This invention concerns snowshoes, especially molded plastic or composite snowshoes, and relates to improvements in the comfort and convenience of use of snowshoes.
Snowshoes are designed to provide enhanced flotation for a person walking over snow and ice surfaces, and to this end the snowshoes place on the user's foot a structure having a surface area larger than that of the foot. A snowshoe has larger dimensions in both length and width than a person's foot, and the lengthwise dimension is increased both forward of and behind the user's foot in order to keep a proper load balance on the snowshoe during use. Thus, the tail of a typical snowshoe extends substantially back from the heel of the user's foot. For this reason, walking with a snowshoe attached to the foot disrupts the normal gait of the user.
The snowshoe thus acts as a relatively long extension to the foot. Especially when considering this extension in the rearward direction, the portion of the user's gait where the heel of the foot would normally contact the ground, and the following motion of the user's foot and lower body extremities, are greatly affected. The extended length at the rear of the snowshoe comes into contact with the terrain surface earliest, and in a location far to the rear of the user's normal heel strike. The snowshoe then rotates about this rear point and produces unnatural rotation and leverage against the user's lower extremities during the portions of the gait cycle that follow, as the snowshoe rotates into full contact with the terrain.
It is an object of this invention to minimize the negative and unnatural effects presented by the presence of a snowshoe on a user's foot, and particularly to address issues associated with the extended length to the rear and the effects of the modified heel strike and subsequent gait-related motions.
The effect of a snowshoe on the natural gait of the user can be minimized by shortening the length of the snowshoe, particularly rear of the boot. This, however, has the negative effect of reducing the flotation area of the shoe, and as noted, proper load balance requires that the design include extensions both fore and aft of the user's foot.
Another approach that has been proposed has been to construct the tail of the snowshoe with an upwardly angled or curving shape. An example of this is a Tubbs snowshoe that can be seen on the website tubbssnowshoes.com. In this way the tail of the snowshoe is less disruptive to the gait of the user than in the case of relative flat tail portion of the same length. Although such an upward curve will somewhat decrease the flotation in this portion of the snowshoe, it will not have as negative an effect as shortening the snowshoe.